The present invention relates to receivers for solar power stations wherein the sunlight is concentrated in the manner of the so-called solar farm principle.
Solar receivers of the just mentioned type are known. Such receivers collect the sunlight in a point type zone or the heat is concentrated in such zone for transferring the heat to a liquid or gaseous heat transport medium. A plurality of collectors of this type feeds the heated medium into a common piping network which in turn is connected to a circulatory system including work performing machines. The collectors are moved to follow the instantaneous position of the sun. However, it is also known to construct the collectors in such a manner that at least within a certain range a movement following the sun is not required.
The use of concentrating receivers or collectors is suitable if the working temperature range is above 150.degree. C. However, such concentrating receivers make it necessary not to utilize the indirect sunlight.
It is necessary that the direct radiation energy must be transmitted to the heated transport medium with a minimum of thermal losses. In addition it is necessary that pressure losses in the heat transport medium are maintained as low as possible when the heat transport medium travels through the absorber in order to keep the energy necessary for the circulation of the heat transport medium as low as possible. Another problem encountered in this context resides in the fact that some of the suitable heat transport media are sensitive against overheating which limits the upper inner wall temperature of the receiver.